<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.bigBox{
				width: 1000px;height: 500px;
				background-color: #eee;
			}
			.top{
				width: 100%;height: 50px;
				background-color: aquamarine;
			}
			.bottom{
				width: 100%;height: 450px;
				background-color: darkcyan;
			}
		</style>
	</head>
	<body>
		<div class="bigBox">
			
			<div class="top"></div>
			
			<div class="bottom">
				
				<div></div>
				<div></div>
				
			</div>
			
			
		</div>
	</body>
</html>